Previously unknown pentaquarks discovered by a Pole
Everything around us is made up of elementary particles called quarks and leptons, ktore can combine to form larger particles, such as protons or atoms. The standard model of the wyro¿nia six typeoin a quarkow. These are quarks gorne (u), lower (d), strange (s), alluring (c), beautiful or low (b) and true or high (t), with each genus also having swoj anti-material counterpart (often indicated by a horizontal dash above the letter, reading as „bar”).
According to wspoAccording to modern knowledge, quarks are the most important indivisible bricks, of whichorich matter folds. On ogo³ are formed in quark-antiquark pairs. They are extremely sociable particles: almost immediately after their creation they bind into hadrons, i.e. sets of twooch, three, and sometimes more quarksoin or antiquarkoin, bonded by gluonow (i.e., particles carrying strong nuclear interactions). The process of quark fusionow/antiquarkow complexes are the so-called. hadronization.
According to the Murray model’and Gell-Mann there are two broad classes of hadronsow. One of these are particles consisting of three quarksow called baryons (including protons and neutrons that form the atomic nucleus). The second are unstable hadrons made of quark-antiquark pairs called mesons.
Until recently, baryons and mesons were the only types of hadronsow, ktore observed in experiments. Back in the 1960s, Gell-Mann postulated the possibility of more exotic combinations of quarksow, such as tetraquarks (two quarks and two antiquarks) and pentaquarks (four quarks and one antiquark).
In 2014, analyses of dozens ofoin thousands of decaysoin mesonoin experiments conducted at the LHCb experiment at the Large Hadron Collideroat CERN confirmed the existence of tetraquarksow. Year poLater, the discovery of the first ever pentaquark was announced, adding a completely new class of particles to the hadron familyow. Professor Skwarnicki took part in this work.
Now scientists working at CERN have announced the discovery of three such particles. This was possible thanks to the large amount of new data recorded during the second launch of the Large Hadron Colliderow.
– We now have ten times more data than in 2015, allowing us to see more exciting and subtler structures than before – said Liming Zhang of Tsinghua University in Beijing, whoory wspohe collaboration with Skwarnicki.
When physicists examined the original pentaquark discovered in 2015, they were surprised to find that it had split into two parts. It turned out that this pentacarbons were actually two pentacarbons, whichore had similar masses and looked like a single particle. In addition, researchers found a third pentaquark with a slightly smaller mass than the other two.
But what is the exact internal structure of these pentaquarksow? One option is that they are actually made of five quarksow, with whichorych all are mixed rouniformly in a single hadron. One bottom quark, dwoch gornych, alluring quark and alluring antiquark. Another possibility is that pentacoquarks are actually baryons and mesons glued together to form a loosely bound particle, just as protons and neutrons combine in an atomic nucleus.
Skwarnicki acknowledged that the most likely option is that these pentacoquarks are baryon-meson particles, although to be absolutely sure, physicists will need more experimental data, as well as further theoretical research.
– Until now, we thought that pentaquarks consisted of five quarksow combined together. Our findings prove otherwise,” admitted Skwarnicki.
In each of these three pentaquarksow is unique in that their mass is slightly less than the sum of the masses of their parts – in this case, the masses of the baryon and meson.
– Pentaquarks may not play an important role in matter, with ktorej we are built, but their existence could significantly affect our models of matter found in other parts of the Universe, such as in neutron stars – Skwarnicki stated.
Professor Tomasz Skwarnicki has lived in the United States for more than 20 years now. He is currently employed at Syracuse University, but the origins of his research career are related to Poland. He studied physics at the Jagiellonian University and earned his doctorate at the Institute of Nuclear Physics of the Polish Academy of Sciences in Krakow.